>> I'm not sure if this is the right approach - what if a bios intentionally> assigns a small area? It's dangerous to override the BIOS setting.> I'd prefer a kernel command line parameter / module parameter / dmi based> override instead of an unconditional override based on the minimum size.> I'll think about it.

A module parameter sounds like a grand idea. I'd be happy to take a stab at it if others feel it is the way to go.